Instrument for thromboembolic protection

Abstract

A thromboembolic capturing system captures thromboemboli in the arterial and venous circulation. A vascular tube such as a guidewire includes a porous filter at is distal end. The filter is collapsible, capable of maintaining open and closed configurations when placed within a vessel. Opening and closing of the filter is controlled by strings or sutures running through the tube. The filter is able to retain captured thromboembolic material in conjunction with angioplasty or interventional cardiovascular procedure. When the tube comprises a guidewire, it is of sufficient strength, torquability and softness to be used for angioplasty, stent placement and other interventional procedures.

What is claimed is:  
     
       1. Apparatus for capturing and retrieving emboli from a blood vessel, the apparatus comprising: 
       a hollow tube having a proximal end and a distal end wherein the distal end is insertable into the vessel;  
       a collapsible filter attached to the tube near the distal end, the filter comprising a plurality of ribs resiliently biased outwardly from the tube and extending axially along the tube from the distal end toward the proximal end, and a filter material bridging the ribs, wherein the filter is extendable radially outward from the tube toward a wall of the blood vessel, at least one of the ribs and/or the filter material are located at a radial outermost portion of the filter when the filter is in an extended position and contacts the wall of the blood vessel, thereby trapping stenosis fragments while allowing passage of blood flow, and the filter is retractable radially toward the tube to retain the trapped fragments while the tube is withdrawn from the blood vessel; and  
       control strings connected to the ribs and running at least partially inside the tube for extending and retracting the filter.  
     
     
       2. The apparatus of  claim 1 , wherein the control strings enter the tube through a collar mounted on the tube. 
     
     
       3. The apparatus of  claim 2 , wherein the collar comprises multiple holes through which the control strings are threaded. 
     
     
       4. The apparatus of  claim 3 , wherein the collar is substantially cylindrical and the holes are substantially equalangularly spaced around a circumference of the collar. 
     
     
       5. The apparatus of  claim 1 , further comprising a core inside the tube. 
     
     
       6. The apparatus of  claim 5 , wherein the control strings are located between an exterior surface of the core and an interior surface of the tube. 
     
     
       7. The apparatus of  claim 5 , wherein the core comprises a tapered distal tip. 
     
     
       8. The apparatus of  claim 5 , wherein the core comprises coiled metal wire. 
     
     
       9. The apparatus of  claim 1 , wherein the tube comprises a guidewire. 
     
     
       10. The apparatus of  claim 9 , wherein the guidewire comprises coiled metal wire. 
     
     
       11. The apparatus of  claim 9 , wherein the control strings enter the guidewire through a collar mounted on the guidewire. 
     
     
       12. The apparatus of  claim 1 , further comprising an actuator at the proximal end of the tube operatively connected to the control strings for extending and retracting the filter. 
     
     
       13. The apparatus of  claim 12 , wherein the control strings are attached at one end to the ribs and at another end to the actuator. 
     
     
       14. The apparatus of  claim 1 , wherein the tube has an outer diameter of from about 0.02 to about 0.1 inch. 
     
     
       15. The apparatus of  claim 1 , wherein the tube comprises a guidewire having an outer diameter of about 0.035 inch and an inner diameter of about 0.022 inch. 
     
     
       16. The apparatus of  claim 1 , wherein the apparatus comprises at least three of the ribs. 
     
     
       17. The apparatus of  claim 1 , wherein the ribs extend substantially linearly along the axial direction of the tube when the ribs are retracted. 
     
     
       18. The apparatus of  claim 1 , wherein the ribs comprise rounded tips. 
     
     
       19. The apparatus of  claim 1 , wherein the ribs comprise metal. 
     
     
       20. The apparatus of  claim 1 , wherein the filter material comprises at least one porous material selected from plastics and metals. 
     
     
       21. The apparatus of  claim 1 , wherein the apparatus comprises at least three of the control strings. 
     
     
       22. The apparatus of  claim 1 , wherein the control strings comprise sutures. 
     
     
       23. Apparatus for capturing and retrieving emboli from a blood vessel, the apparatus comprising: 
       a hollow tube comprising a guidewire and having a proximal end and a distal end wherein the distal end is insertable into the vessel;  
       a collapsible filter attached to the tube near the distal end, the filter comprising a plurality of ribs resiliently biased outwardly from the tube and extending axially along the tube from the distal end toward the proximal end, and a filter material bridging the ribs, wherein the filter is extendable radially outward from the tube toward a wall of the blood vessel to trap stenosis fragments while allowing passage of blood flow, and retractable radially toward the tube to retain the trapped fragments while the tube is withdrawn from the blood vessels; and  
       control strings connected to the ribs and running at least partially inside the guidewire for extending and retracting the filter, wherein the control strings enter the guidewire through a collar mounted on the guidewire.  
     
     
       24. Apparatus for capturing and retrieving emboli from a blood vessel, the apparatus comprising: 
       a hollow tube having a proximal end and a distal end wherein the distal end is insertable into the vessel;  
       a collapsible filter attached to the tube near the distal end, the filter comprising a plurality of ribs resiliently biased outwardly from the tube and extending axially along the tube from the distal end toward the proximal end, and a filter material bridging the ribs, wherein the filter is extendable radially outward from the tube toward a wall of the blood vessel to trap stenosis fragments while allowing passage of blood flow, and retractable radially toward the tube to retain the trapped fragments while the tube is withdrawn from the blood vessels; and  
       control strings connected to the ribs and running at least partially inside the tube for extending and retracting the filter, wherein the control strings enter the tube through a collar mounted on the tube.  
     
     
       25. Apparatus for capturing and retrieving emboli from a blood vessel, the apparatus comprising: 
       a hollow tube having a proximal end and a distal end wherein the distal end is insertable into the vessel;  
       a collapsible filter attached to the tube near the distal end, the filter comprising a plurality of ribs resiliently biased outwardly from the tube and extending axially along the tube from the distal end toward the proximal end, wherein the ribs comprise rounded tips, and a filter material bridging the ribs, wherein the filter is extendable radially outward from the tube toward a wall of the blood vessel to trap stenosis fragments while allowing passage of blood flow, and retractable radially toward the tube to retain the trapped fragments while the tube is withdrawn from the blood vessels; and  
       control strings connected to the ribs and running at least partially inside the tube for extending and retracting the filter.